4.1 Equipment should continue to operate in accordance
with the requirements of this Recommendation in the presence of variations
of power supply normally to be expected in a ship.
4.2 Means should be incorporated for the protection
of equipment from the effects of excessive current and voltage, transients
and accidental reversal of the power supply polarity.
4.3 If provision is made for operating equipment
from more than one source of electrical energy, arrangements for rapidly
changing from one source to the other should be provided but not necessarily
incorporated in the equipment.